Which Aortic Dissection Patients Need CT Aortography?

Aortic dissection is a high-mortality vascular emergency that can present with almost any symptom, not just classic tearing chest pain. CT aortography is the diagnostic test that rules it in or out and guides surgery, so the real ED question is which patients need CTA now.

Aortic Dissection Recognition and Imaging

• Extreme early mortality: Aortic dissection kills fast, with roughly 40% mortality at presentation and ongoing hourly risk, so delayed recognition is dangerous even when the first complaint seems atypical.
• Aorta perfuses every organ: Because the aorta supplies every vascular bed, dissection can masquerade as neurologic, abdominal, limb-ischemic, or syncope presentations rather than straightforward chest pain.
• Risk factor features: Connective tissue disease, bicuspid aortic valve, prior aortic disease or procedure, pregnancy, and sudden blood-pressure surges should all lower your threshold for CTA.
• Pain pattern clues: Abrupt severe chest or back pain, especially when described as ripping, posteriorly radiating, or migratory, is a classic pattern that should trigger dissection thinking.
• Chest pain plus-one findings: Chest pain paired with syncope, neurologic symptoms, extremity malperfusion, or GI symptoms is a practical bedside pattern for deciding who needs CTA. We walk through that trigger in the episode.
• Exam and CXR red flags: Pulse deficits, an inter-arm pressure difference over 20 mmHg, hypotension, aortic insufficiency murmur, focal deficits, or a widened mediastinum all raise the pretest probability.

ED Management Before the Operating Room

• CTA as the decisive test: CT aortography is the study of choice for diagnosis and operative planning, and very few patients are truly too unstable for CT if you resuscitate first.
• Unstable patient pathway: If dissection is strongly suspected in an unstable patient, intubation or vasopressors may be needed simply to get the patient to CTA and then to the OR.
• Ultrasound rule-in only: Transthoracic ultrasound is helpful when positive but a negative exam does not exclude dissection, whereas TEE can both diagnose and exclude disease when available.
• Analgesia and anxiolysis first: Pain and anxiety control are core therapy because catecholamine surge worsens shear stress; IV opioids and benzodiazepines are favored, while ketamine is avoided.
• Heart rate before pressure: Impulse control comes first: lower heart rate before blood pressure to avoid reflex tachycardia, with esmolol as the preferred titratable first-line agent.
• Hypotension and tamponade rescue: Hypotension in dissection is a grave sign, and pericardial tamponade is the key ED-reversible cause; drainage should remove only enough blood to restore perfusion. We get into that nuance in the chapter.

References:

1. Hameed I, Cifu AS, Vallabhajosyula P. Management of Thoracic Aortic Dissection. JAMA. 2023 Mar 7;329(9):756-757. PMID: 36795378.
2. Strayer RJ. Thoracic Aortic Syndromes. Emerg Med Clin North Am. 2017 Nov;35(4):713-725.  PMID: 28987425.
3. Elefteriades JA, Barrett PW, Kopf GS. Litigation in nontraumatic aortic diseases--a tempest in the malpractice maelstrom. Cardiology. 2008;109(4):263-72.  Epub 2007 Sep 17. PMID: 17873491.